Coffer-dam



Apnfi 5, 19% s. PERKINS 2,931,137

COFFER-DAM Filed July 8, 1957 2 Sheets-Sheet 1 k -w uuu LL-J 11:2

w 49 INVENTOR.

Starling Perkins.

Aprifl 5, 1960 s. PERKINS COFFER-DAM Filed July 8, 1957 2 Sheets-Sheet 2 fly: 6, /33 I INVENTOR Starlmg Perk/nae ATTORNEYS.

United States Patent 2,931,187 Patented Apr. 5, 1960 free COFFER-DAM Starling Perkins, Chouteau, Okla.

Application July 8, 1957, Serial No. 670,512

5 Claims. (Cl. 6182) This invention relates to coffer-dams such as used in sinking shafts, tunneling and other operations requiring a casing for holding back the earth and fluid through which the project is extended and is an improvement over my Patent No. 2,596,788 of May 13, 1952.

It is the principal object of the present invention to provide additional load space between the walls of the inner and outer caissons for use of water or other material for ballast load in sinking the caissons; to provide for maintaining a flow of pressure fluids after the cofferdam is in position to prevent external fluids from entering therein while the soil and other matter is being removed from the interior or the cofler-dam; to provide for injection of the fluid within the compartments of the respective sections of the Coffer-dam to sink the same; to provide means for controlling the sinking of the coflerdam; to provide means for securing the sections of the coffer-dam together of relatively simple structure and wherein the sections are readily inter-connected for assembly and disassembly; to provide means for freezing the soil and fluids at the base of the hole to assist in drying the interior so that the soil may be excavated and the desired structure built therein, and to provide the sections with excavating jets and other means to effect the placement of the cfferdam and operations that are to be performed therewith.

In accomplishing these and other objects of my invention, I have provided improved details of structure the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a vertical sectional fragmentary view of my invention particularly illustrating the compartments for additional weight of fluid or other matter for sinking the cotter-dam.

Fig. 2 is a vertical sectional fragmentary view showing the portion of the Coffer-dam with concrete placed therein after digging of the hole and with the parts of the structure which will remain permanently therein.

Fig. 3 is an enlarged vertical sectional fragmentary view particularly illustrating the fastening of the sections together.

Fig. 4 is an enlarged vertical sectional fragmentary view particularly illustrating the pressure chamber and freezing unit.

Fig. 5 is a cross-sectional view taken on a line 5-5, Fig. 1.

Fig. 6 is a vertical sectional fragmentary view of a modified form of the invention particularly illustrating the lining between the sections for easy removal of said sections.

Fig. 7 is an enlarged sectional fragmentary view illustrating the flow of fluid to the respective compartments.

Referring more in detail to the drawings:

1 designates a coffer-dam constructed in accordance with the present invention preferably of cylindrical shape and the wall structure comprising two or more sections depending upon the size of the dam. Any suitable crosssectional shape may be utilized to conform with the shaft to be sunk into an earth formation.

I have here illustrated the respective caisson sections to be of cylindrical form but they may also be of two sections in semi-cylindrical form as illustrated in my Patent No. 2,596,788 and when so formed are connected as by the connecting means particularly illustrated in Fig. 2 of Patent No. 2,596,788.

In the present illustration I have shown a base member 2 with a plurality of sections 3, 4 and 5 connected thereto, although any number may be utilized depending upon the job to be done. As illustrated A represents the outer Wall or caisson, B the spaced Wall or next caisson, and C the inner wall or caisson also made in sections as will later be shown.

Secured rigidly by welding or other suitable means as indicated at 6 (Fig. 3) to the inside of the upper portion of the section 2 are a plurality of I-bearns 7 (Fig. 5) depending radially inwardly and spaced from each other and rigidly secured thereto by welding or other suitable means is a cylindrical ring 8 having an offset portion 9 and an upstanding flange or collar 18 (Fig. 2). Welded or otherwise rigidly secured to opposite diametric sides of the inner wall of the section 2 and spaced slightly lower than the upper edge 11 thereof is a plurality of U-shaped members 12 in which are adapted to engage threaded nuts or bushings 13 for a purpose later described. In order to join section 3 with section 2, I preferably secure by welding or the like metal bands or rings 14 and 15 to the inner and outer side of the wall A with said rings extending below the edge 16 of said caisson thus providing a space 17 between the rings for receiving the upper edge 11 of the section 2. In order to seal the sections I provide a rubber ring 18 or the like to make an air-tight connection. In order to hold the sections 2 and 3 in rigid relation, spaced slightly from the upper edge 19 of section 3 and in alignment with the U-shaped member 12 are U-shaped members 28. The horizontal flanges of the U-shaped members 28 being provided with aligned openings and the U-shaped member 12 also having an opening 21 in the upper flange thereof aligned with a threaded bore in the nut 13 for receiving tie belts or the like 22. The heads 23 of the bolts engage the upper flange of the U-shaped member 20 whereas the shanks of said bolts extend through washers 24 between the horizontal flanges and their threaded lower end 25 engages in the nut 13 whereby upon tightening of the bolts the sections come together in a tight seal made between the connection. The heads 23 are serrated or notched as at 26 to receive the socket of a tool for tightening or loosening the same (not shown).

The lower edges of the sections 4 and 5 are provided with metal bands or rings the same as rings 14 and 15 for securing the neck of the adjacent section thereto. The horizontal flanges of the U-shaped member 20 extend further inwardly than the member 12 and are provided with aligned openings and between said openings are threaded nuts 27 for receiving the threaded ends 28 of connecting bolts 29 having their heads 38 engaging on U-shaped is engaged within the flange or collar 10 on the ring member 8 also as illustrated in Fig. 1. The upper end of section 33 is offset and provided with an annular flange or collar 36 for receiving the end 37 of the section 34. Hook or handle members 38 are provided on the respective sections, here shown to be on the collar 36 for attachment of suitable means for raising or lowering the sections in the caisson A.

The lower section 2 of the present invention is constructed substantially similar to the lower section shown in my Patent No. 2,596,788 which primarily consists of the downwardly extending flange 39 forming a cutting edge 40 on the lower edge of the section 2. Spaced from the lower edge is a U-shaped ring member 41 preferably Welded to the inner wall of the section 2 forming a chamber 42 for suitable refrigerating coils 43 to freeze the liquid immediately surrounding the lower edge of the coder-dam sections to further prevent leakage of external water into the colfer-dam and further assist in drying out the interior formation to facilitate removal thereof as will later be described. A ring member 44- is provided within the chamber 42 along the inside of the caisson wall A slightly spaced therefrom and between the ring 44 and wall A are layers of screening as indicated at 45. The ring 44 and wall A have aligned openings 46 to provide access to the liquid surrounding the outer and lower portion of caisson A for said freezing purpose. A similar ring 47 is provided inside of the vertical portion of the U-shaped ring 41 with layers of screening 48 between said vertical portion and ring 47. The vertical portion and ring 47 have openings 49 to allow access for the freezing elements to the interior of the caisson.

Mounted on the flange 58 of the U-shaped ring member 41 and welded thereto or otherwise suitably secured is a cone-shaped housing 51, the lower edge terminating in a depending skirt 52 extending to substantially the upper part of the vertical portion of the U-shaped ring 41. The uper end of the cone shaped housing 51 is provided with a threat 53 having on its upper end laterally turned flange 54 to which may be attached the caisson C as illustrated in Figs. 1 and 2. The caisson C is divided into sections 55 and each end is provided with a laterally turned flange as indicated at 56 so that the sections may be secured together as by bolts or the like 57 and sealing means such as gaskets or the like may be used between the sections to form a water-tight structure.

Spaced from the flange 59 of the Ushaped ring member 41 is an annular plate 58 having its outer edge welded to the inner walls of the section 2 as indicated at 59 forming a compartment 6h above the chamber 42. A cylindrical ring 61 is spaced inside from the wall of the section 2 and a screening 61' is placed between the ring 61 and the wall A, the latter being provided with aligned openings 62 similar to the openings 46 in the chamber 42 for a purpose later described. I he lower end of the coneshaped housing 51 is provided within the compartment 60 with a spaced cone-shaped ring member 63 and screening 64 is placed therebetween and the ring member 63 and lower end of the housing 51 are provided with openings 65 (Fig. 4) also for a purpose later described.

The plate 58 has a plurality of spaced openings 66 and welded or otherwise suitably secured therein are a plurality of ducts 67 which extend through the throat 53 into the caisson C and have connections on their upper ends near the fiange 54 as indicated at 68 to which are attached detachably connected tubings 69 for delivering fluid under pressure to the compartment 60 as later described. The freezing unit consisting of the tubing 43 in the chamber 42 connected with ducts 70 (Fig. 4) which extend through the wall of the throat 53 as indicated at "i1 and has a coupling connection 72 with tubings 73 which extend upwardly through the caisson C. As illustrated in Fig. 5, there may be a plurality of these tubings which connect with the freezing units.

The tubings 69 are supplied with a pressure fluid from a source of supply (not shown) to the ducts 67 leading to the compartment for discharging the pressure fluid into the compartment for outlet through the openings 62 and in the outer wall of section 2 and the inner portion of the cone-shaped member 51 so that the pressure fluid will carry away the soil and other matter up the outer wall A of the coder-dam section and will also flow the soil and other matter upwardly through the caisson C. If the soil conditions are such that an upward flow of soil in caisson C is hard to accomplish, clam buckets or the like may be lowered through caisson C to remove the loose soil in the cone-shaped housing 51. The compartment 60 will fill with liquid which adds weight in cooperation of the excavating action of the jets or openings 62 and 65 to effect sinking of the cofferdam to its desired position.

After reaching the desired position, air pressure may be admitted to the compartment 60 for displacing the water therefrom to hold back the extremal liquid and also into the interior of the coifer-dam and the water may be pumped therefrom by suitable means (not shown) to dry up the core and air pressure may be maintained while the soil of the core is being exacavated to permit installation of a pier or other structure for which the shaft is formed as illustrated in my Patent No. 2,596,788.

In using the confer-dam the sections are transported to the site of operation and one section is stood in vertical position with the lower cutting edge thereof supported on the surface of the ground, for example, on the bed of a stream into which the coffer-dam is to be placed and the other section is supported in proper relation to the mating flanges and sealing means whereupon the section is lowered into position until the cutting edge thereof rests upon the bed of the stream. The sections, when thus related, form a circular Coffer-dam which encircles the site of the shaft to be excavated.

In use of my apparatus, assembled as described, the caisson B or the wall 75 is not formed with the apparatus above described but is only used independently of the caissons A and C. This is temporary and constructed at the operating site, as it may be necessary to shift the desired relation of the sections so that they may be adjusted to substantially the center of the structure. The wall 75 comprising the caisson B is only used for constructing of concrete piers or the like and for ballast where more loading is needed for greater depth of water. In Fig. 2 I have illustrated the apparatus after the concrete has been poured and the tubing removed therefrom as well as caissons A and B with the exception of section 2. After the caisson C is installed as above described then the concrete is poured down through the caisson C into the housing 51 after removal of the tubings 69 and 73. Then the caisson B is filled with concrete which will first fill up the space in section 2 around the housing 51 and then upwardly within the caisson B to the desired height. When the concrete is set the sections 33 and 34 of the caisson B are removed as well as the sections 3, 4 and 5 of the caisson A. The caisson C will remain and act as a reinforcement for the concrete and also the lower section 2 for the cotter-dam is left in place to form a part of the pier footing or the like (Fig. 2). The caisson A can be constructed of heavy plate steel with suiiicient strength to support outer pressure or can be made from lighter steel plate reinforced with heavy steel bands or channels bent to the inside radius and welded to walls of caisson A.

in Figs. 6 and 7, I have illustrated a modified form of invention wherein the outer wall A and inner tubing or caisson C are the same as in the preferred form of the invention, and the wall or caisson B is used only when a concrete structure is desired. When an enlarged concrcte footing or ballast is required approximately to a point 76 as shown in dotted lines (Fig. 6) an insulation 77 is placed against the inside of the caisson wall A to prevent the concrete from bonding thereto. I have also found that the bolts or rods 22 will work better by sleeving the same as indicated at 78 so the concrete will not bond thereto.

The cone-shaped housing 51 is the same as in the preferred form of the invention and has an elongated depending skirt '79 spaced from the walls of section 2 to terminate short of the lower edge 80 of said section. It is connected to the section by an angle ring member 81 with a vertical leg 82 thereof welded or otherwise suitably secured to the wall of section 2 and reinforced thereto by a ring 83. Spaced upwardly from the angle shaped member 82 is a similar angle shaped member 84 with its vertical leg 85 welded to the inside of section 2 and its horizontal section welded to the skirt of the cone-shaped member forming a lower compartment 86. Another angle shaped member 87 is spaced upwardly from the member 84 with its vertical leg 88 secured to the wall of section 2 and its horizontal portion welded to the coneshaped member as indicated at 89 forming an upper compartment 90. A perforated wall 91 spaced from the wall of section 2 is joined to the vertical leg 85 of the angle shaped member 84 and is also welded or otherwise suitably secured to the angle shaped member 82. Located between the perforated wall 91 and the wall of section 2 is a layer of screening 92 and the wall of section 2 is perforated as indicated at 93 to allow fluid to flow through the outer walls 91 and 93 of compartment 86. A perforated wall 94 is also secured to the vertical leg 88 of the angle member 87 and to the angle member 84 and located between the perforated member and the Wall of section 2 is a layer of screening 95. The wall of section 2 adjacent the wall 94 is perforated as indicated at 96 to allow fluid to pass to and from compartment 90. Built within the compartment 86 is a chamber 97 formed by an angle shaped member 98 and a perforated side 99 which is covered by a screening 100. The lower edge of the skirt 79 of the cone-shaped housing 51 is perforated as indicated at 101 for passage of fluid to and from com partment 97. v

Formed in the compartments 86 and 90 and supported upon the vertical flanges of the angle shaped ring members 81 and 84 immediately adjacent the perforated walls 91 and 94 are ducts 102 and 103 having a plurality of apertures 104 through which pressure fluid is discharged for outlet through the perforated walls 91, 93 and 94, 96, as later described. The ducts 102 and 103 are supplied with pressure fluid through ducts 105 and 106 leading upwardly along the outside of the housing 51 and then into the caisson C the same as ducts 69 and 73in the preferred form of my invention. A supply duct 107 has connection With the chamber 97 and extends also upwardly into caisson C. Air pipes 108 and 109 lead into the compartments 86 and 90 for a purpose later described. All upwardly leading ducts have coupling connections 1-10 with tubings 111 in the caisson C for disconnecting said tubings in case section 2 should remain permanently in the ground (Fig. 2) the tubings 111 leading to a source of supply (not shown).

In using the modified form, the coifer-dam is assembled as described in the preferred form of my invention and lowered for example, into the bed of a stream. In order to sink the coifer-dam into the soilthe respective ducts are connected and liquid under pressure is forced through the ducts 105, 102 and 106, 103 into the compartments 86 and 90 and is discharged through the jet openings or perforations in the walls 91 and 94 and through the openings in section 2 to displace and move upwardly the soil into which the coffer-dam is to be sunk. Simultaneously, liquid under pressure is supplied through duct 107 into chamber 97 and discharged therefrom through openings 101 in the depending skirt '79 to effect a similar upflow of liquid and soil along the inside of the housing 51 and through caisson C. The compartments 86 and 90 fill with liquid'which adds weight in cooperation with the excavating action of the jets to effect sinking of the cofier-dam to its desired position. When the coffer-dam is in its desired position, air under pressure is admitted through the pipes 108 and 109 to force the liquid out of the compartments 86 and 90 through the jet openings. As the compartments empty, the air is discharged through the openings to hold back the external liquids which might 6 tend to pass under the coifer-da-m. Similar jets of air may be discharged through the perforations 101 into the interior of the coifer-dam or housing 51 and the water may be pumped from the interior by suitable means (not shown) upwardly in caisson C to dry up the core.

For constructing a concrete pier or the like, caisson B is lowered into caisson A and placed within the offset portion 9 of the cylindrical ring 8 which is rigidly secured to section 2 of caisson A by the I-beam '7. Additional sections of caisson B may be set on top of each other to a point above the Water-line and concrete is poured downwardly to fill section 2 and caisson B. Before disconnecting of the tubings 111 concrete is poured into caisson C to fill the inside of the housing 51 as well as the inside of caisson C. When the concrete has settled the bolts 22 are disconnected and the caisson A sections 3, 4 and 5 are removed with the exception of section 2. Then caisson B is removed whereas caisson C and housing 51 remain as reinforcement in the pier as described in the preferred form of my invention.

The form shown in Figs. 6 and 7 may also be provided with suitable refrigerating coils i ncompartment 86 thereof (not shown) to freeze the liquids surrounding the lower edge of the coifer-dam to further prevent l'eakage and assist in drying out the interior.

It will be obvious that any amount of caisson sections may be added to so that they extend to the top of the formation and form an enclosure through which the soil within the coffer-dam is excavated upon final setting of the coifer-dam.

A coffer-dam constructed as described may have many uses for sinking of ,wells or the like in which case a pump (not shown) may be used for removing water which flows from the water producing formation into which the coifer-dam is sunk into the compartments through the apertures. I

It will be obvious from the foregoing that I have provided an improved coffer-dam structure that is simple and inexpensive to construct for the removal of sand and other material therethrough.

What I claim and desire to secure by Letters Patent is:

1. An apparatus for forming a coffer-dam comprising, a plurality of longitudinally aligned hollow sections defining a chamber and having interengaging end edges, said interengaging end edges including seal means for forming a fluid tight seal, releasable means for securing said sections in end to end fluid tight relation, the bottom said section having an open bottom end, a housing in said bottom section defining a closed bottom for said chamber and opening downwardly, a caisson extending axially through said chamber and in communication with the interior of said casing for carrying fluids under high pressure to and from said housing interior, a second caisson having an open bottom extending co-axially with and of larger diameter than the first named caisson, means releasably engaging the bottom end edges of said second caisson for supporting the same in spaced relation to said housing whereby said second caisson is in communication with the bottom portion of said chamber above said housing, and means for jetting fluid under high pressure into the interior of said housing.

2. An apparatus for forming a coifer-dam comprising, a plurality of longitudinally aligned hollow sections in end to end engagement defining a chamber, continuous bands secured to the bottom portion of each engaging section and extending below the bottom end edge of the respective sections to define a slot for receiving the upper end edge of the next succeeding section, seal means in said slot for forming a fluid tight seal between the respective sections, releasable means for securing said sections in end to end fluid tight relation, the bottom said section having an open bottom end, a housing in said bottom section defining a closed bottom for said chamber and opening downwardly, a caisson extending axially through said chamber and in communication with the interior of said housing for carrying fluids under high pressure to and from said housing interior, a second caisson having an open bottom extending co-axially with and of larger diameter than the first named caisson, a collar in said chamber and releasably engaging the bottom end edge of said second caisson tor supporting the same in spaced relation to said housing whereby said second caisson is in communication ,with the bottom potrion of said chamber above said housing, means for jetting fluid under high pressure into the interior of said housing, and refrigeration means adjacent the bottom edge of said bottom section. p

3. An apparatus for forming a cotter-dam comprising, a plurality of longitudinally aligned hollow sections defining a chamber and having interengaging end edges,

said interengaging end edges including seal means for forming a fluid tight seal, U-shape members secured to the upper portion of each section and extending into said chamber, each said U-shaped member having aligned openings and a nut with a threaded bore, the aligned openings of one U-shaped member being in vertical alignment with the threaded bore of the nut in the U-shaped member on the next lower section, elongate rods having one end threaded extending through the aligned openings of the respective U-shaped member and having said one end threaded into the nut in the next lower U-shaped member for releasably securing said sections in end to end fluid tight relation, the bottom said section having an open bottom end, a housing in said bottom section defining a closed bottom for said chamber and opening downwardly, a caisson extending axially through said chamber and in communication with the interior of said housing for carrying fluids under high pressure to and from said housing interior, a second caisson having an open bottom and extending co-axially with and of larger diameter than the first named caisson, means releasably engaging the bottom end edges of said second caisson for supporting the same in spaced relation to said housing whereby said second caisson is in communication with the bottom portion of said chamber above said housing, and means for jetting fluid under high pressure into the interior of said housing.

4. An apparatus for forming a cotter-dam comprising, an outer wall composed of a plurality of longitudinally aligned hollow sections defining a chamber and having interengageable end edges in fluid tight relation, the bottom said section opening downwardly, a housing in said bottom section opening downwardly and having an open throat substantially axially of said bottom section, said housing having walls tapering outwardly from said throat and terminating in a depending skirt portion spaced from the outer wall of said bottom section, transverse plate members spaced apart and secured to said outer wall and said depending skirt to define a plurality of compartments between said skirt and outer wall, said plate members cooperating with said housing to form a closed bottom for said chamber, a caisson extending substantially axially of said chamber and having the bottom end thereof releasably secured in fluid tight relation to said throat in communication with the interior of the housing, a collar in the upper portion of said bottom section and spaced above the tapering Walls of said housing, rigid means extending radially from said collar and secured to said outer wall for supporting said collar, a second caisson of substantially larger diameter than the first named caisson co-axially therewith to define a passageway between said first and second caissons, said collar having an oflset portion for receiving the bottom end of said second caisson with said passageway opening into i said chamber above the tapered wall of said housing of said outer wall sections in fluid tight relation, refrigeration means in the lowermost said compartments, said compartments having openings communicating through said outer wall and into said housing, and means for discharging fluid under high pressure through the openings in the compartment above said lowermost compartmerit, the last named means being separable near the top of said bottom section whereby the bottom section and first named caisson are separable from the remainder of the cotter-dam to permit removal of said remainder leaving said bottom section and first named caisson as reinforcing structure. 7

5. An apparatus for forming a cotter-darn comprising, an outer wall composed of a plurality of longitudinally aligned hollow sections in end to end engagement defining a chamber, continuous bands secured to the bottom portion of each engaging section and extending below the bottom end edge of the respective section to define a slot for receiving the upper end edge of the next succeeding section, seal means in said slot for forming a fluid tight seal between the respective sections, the bottom said section opening downwardly and having a downwardly extending flange on the bottom end defining a cutting edge, a housing in said bottom section opening downwardly and having an open throat substantially axially of said bottom section, said housing having walls tapering outwardly from said throat and terminating in a depending skirt portion spaced from the outer wall of said bottom section, transverse plate members spaced apart and secured to said outer wall and said depending skirt to define a plurality of compartments between said skirt and outer wall, said plate members cooperating with said housing to form a closed bottom for said chamber, a caisson extending substantially axially of said chamber and having the bottom end thereof releasably secured in fluid tight relation to said throat in communi cation with the interior of the housing, a collar in the upper portion of said bottom section and spaced above the tapering walls of said housing, rigid means extending radially from said collar and secured to said outer wall for supporting said collar, a second caisson of substantially larger diameter than the first named caisson extends ing co-axially therewith to define a passageway between said first and second caissons, said collar having an oflset portion for receiving the bottom end of said second caisson with said passageway opening into said chamber above the tapered wall of said housing whereby the chamber may be filled with and emptied of fluid to regulate the downward force on said cutting edge, releasable means for securing the engaging end edges of said outer wall sections in fluid tight relation, refrigeration means in the lowermost said compartment, said compartments having openings communicating through said outer wall and into said housing, and means for discharging fluid under high pressure through the openings in the compartments above said lowermost compartment, the last named means being separable near the top of said bottom section whereby the bottom section and first named caisson are separable from the remainder of the cotter-dam to permit removal of said remainder leaving said bottom section and first named caisson as'reinforcing structure.

References (Iited in the file of this patent UNITED STATES PATENTS 1,025,614 Edwards May 7, 1912.

1,853,379 Rotinofi Apr. 12, 1932 2,010,199 Rotinoft Aug. 6, 1935 2,596,788 Perkins May 13, 1952 FOREIGN PATENTS 31,682. Netherlands Dec. 15, 1933 205,340 Australia Ian. 9, 1957 

